Objective: Multiple pregnancies is a high-risk pregnancy since it is associated with increased perinatal and maternal problems .The aim of our study to determine the frequency of multiple pregnancy and its maternal and perinatal complications.Material & Methods: In a cross –sectional study we assessed 94 multiple pregnancies and 199 neonates in three educational hospitals in Tehran (Baghiyatallah , Najmie and Mahdie) in first half of 2006. The information was collected from hospital registries of mothers and their neonates.Findings: Of 4584 deliveries, 84(1.8%) were twins, 9(0.19%) were triplets and 1(0.02%) was quadruplets. 59 (62.7%) of mothers had preterm labor and 14 (14.8%) had pre-eclampsia. We found discordant birth weigh ≥ 20% in 24 (25.4%) and TTTS (Twin-To-Twin Transfusion) in 3(3.1%) of mothers .174 (87.4%) of all neonates were admitted in NICU or pediatric department. The frequency of mortality and respiratory distress in neonates were 27 (13.5%) and 107 (53.7 %), respectively.39 (19.5%) of neonates had Apgar scores<7 and seizure was not observed in neonates. 65 (32.6%) of neonates were normal weight (> 2500 gram), 104 (52.4%) LBV, 21(10.5%) VLBV and 9(4.5%) ELBV. Hypocalcaemia, hypoglycemia and anemia detected in 45 (22.6%), 24 (12%) and 48 (24.1%) of neonates respectively.Conclusion: Regard to increasing the prevalence of multiple pregnancies, better use of infertility modalities, early diagnosis of the multiple pregnancies, prevention of preterm birth, close fetal surveillance, atraumatic labor and delivery can improve maternal and perinatal outcome.